It is a story familiar to any Chinese student: Thomas Edison, as a boy of seven, came up with an invention that saved his mother from almost certain death. The story has appeared in Chinese primary school textbooks dating back to the 1980s as a potent lesson in the value of ingenuity and family loyalty. The “Napoleon of invention,” as Edison was called, was also a paragon of filial piety.

But the real invention in this case is the story itself and the lengthy tenure of a piece of fiction in Chinese textbooks has renewed anxieties over how and what China is teaching its children in the modern era.

“A textbook is published to transmit the most accurate knowledge and perspectives on the values of us as human beings,” said Yan Lingjun, a Chinese teacher at Shenzhen Yucai Middle School in Guangdong province, who has compiled his own set of 14 textbooks. “It can’t be assembled behind closed doors or use made-up historical facts in service of some kind of political or moral education. How can a textbook include fake knowledge?”

In the story as it is has long been taught to Chinese second graders, Edison’s mother falls gravely ill with appendicitis and requires surgery. But by the time a surgeon arrives at the family home, darkness has fallen. The candles, the doctor judges, are too dim to properly light the procedure – and by morning, the ill woman will likely be dead.

Enter the boy Edison, who in a flourish of creative brilliance ingeniously arranges mirrors in such a way that they concentrate the candlelight, allowing the surgeon to work – and admiringly say of Edison: “We are so lucky this child was here today. He is such a smart boy!”

The mother lives – and, more than a century later so, too, has the story, at least in China.

In the version of the second-grade language and literature class textbook still in use today, “Edison saves his mother” occupies pages 137 to 139. It makes no reference to the inventor’s manifold contributions, including the phonograph, devices for recording and displaying motion pictures, and what has been called the world’s first long-life incandescent light bulb.

Instead, the story offers a lesson in moral conduct and is used to teach children new Chinese characters, including ones that mean “enlighten” and “praise.”

But “it has no basis in fact,” said Paul Israel, director and general editor of the Thomas A. Edison Papers at Rutgers University and a leading authority on the U.S. innovator. It is instead “a fictional event created for the 1940 movie Young Tom Edison starring Mickey Rooney.”

The film version of the doctor offers his words of awe to Edison. “My boy, that mirror was an inspiration,” he says. It is one of a series of invented scenes.

“Entire dissertations could be written about the apocrypha in that film,” said Randall Stross, author of The Wizard of Menlo Park: How Thomas Alva Edison Invented the Modern World.

Even in China, anyone paying attention has for years known the story is not true. As far back as 2009, Chinese scholars called it out as fake, prompting textbook publisher People’s Education Press to remove the tale from its website.

Then this spring, Zhang Min, the headmaster of a primary school in Hangzhou, noticed the story still in textbooks. It had returned to the People’s Education Press website, too.

Mr. Zhang took to China’s Twitter-like Weibo to express his displeasure. “Textbooks have a bearing on the future of a country. It’s an extremely serious matter,” he said in an interview.

The controversy provoked by his post prompted People’s Education Press to promise that the story will not appear in a new version of the textbook that is due out this September.

But the debate it has stirred continues.

China has rewritten textbooks numerous times over the past few decades, most recently aiming to push Chinese students away from rote learning and toward cultivating student curiosity and teaching skills more useful to everyday life.

The long-lived Edison story has raised questions about how much change is actually happening.

“Even if textbook reform takes time, how can eight years not be enough? How many children have read such a false text in eight years? How long can a person be fooled?” Mr. Zhang wrote in one Weibo post.

China, of course, is hardly the only place plagued by disputes over textbooks, whose contents create controversy the world over. But Mr. Zhang lamented what the Edison story intimates about life in a country afflicted by forgeries and polluted public goods.

“From the air, to the food and vaccination – maybe we have begun to take what is counterfeit and toxic for granted, and grown numb,” he wrote.

The Edison story also speaks to the pernicious effect of propaganda on Chinese schools dating back to the Communist Revolution.

“I used to say that the material in Chinese textbooks was packed with lies,” said Mr. Yan, the teacher and textbook author.

“The government has tried to make political the teaching of Chinese since the founding of New China. When we studied in school, half of the textbooks were Chairman Mao quotes.”

That impulse continues.

Beginning in 2001, Chinese authorities set out on a sweeping series of textbook reforms designed to strengthen “the ideological and moral construction of our youths,” which included deliberate attempts to alter classroom materials in ways that would breed loyalty to the Communist Party and increase skepticism of Western forms of government and economic structure.

A landmark 2015 study of high-school graduates by researchers at Chinese, German, U.S. and Hong Kong institutions found authorities had largely accomplished their task.

“The new curriculum was often successful in changing students’ attitudes on important issues, in the direction intended by the Chinese government,” they wrote in a 116-page report titled Curriculum and Ideology.

Students exposed to the new materials “have greater trust in government officials, view government officials as more civic-minded, and see bribery as less prevalent and effective.”

Still, even Mr. Zhang said it’s unfair to hold textbooks to a standard of ceaseless perfection, particularly as time passes, society changes and scientific understanding deepens. “Textbooks are not canonical works like the Bible,” he said.

Mr. Israel, the Edison historian, was also willing to cut the Chinese textbook editors some slack.

“The problem with Hollywood biopics in general is that they become the life story that people know,” he said.

“That is true in the U.S., and it would not be surprising if someone in China thought these movies were a serious retelling of Edison’s life.”